Patent FR-A-2 651 729 discloses a vehicle equipped with a plurality of displacement members, at least certain of which being coupled to a fluid motor and comprising a pressurized fluid supply circuit comprising, in addition to said motors: a source of pressurized fluid connected to a fluid delivery conduit; at least two fluid supply conduits each connected, on the one hand, in parallel, to said fluid delivery conduit, on the other hand, to a particular one of said fluid motors, the latter each comprising a fluid exhaust conduit; and devices for measuring the speed of at least those of the displacement members coupled to said particular motors; as well as the following characteristic features: a) restrictions of adjustable values are disposed on at least one of the fluid supply and fluid exhaust conduits of said particular motors, one on each fluid supply and/or fluid exhaust conduit, and are provided with individual devices for adjusting their values; b) a reference speed of displacement members is selected; c) a processing device, incorporated in the vehicle, compares each measured speed of said displacement members coupled to the particular motors, with said reference speed and generates, for each particular motor, a correction signal, the processing device comprising as many output connections, where the correction signals are available, as there are restrictions, each correction signal corresponding to the measured speed of a displacement member coupled to one of said particular motors; d) each outlet connection is connected to the device for adjusting the value of the restriction placed on the fluid supply conduit or on the fluid exhaust conduit of the particular motor corresponding to the correction signal generated by the processing device from the measured speed of the displacement member coupled to said particular motor.
It is commonplace for a vehicle to move over sloping ground. When descending a slope, the vehicle as defined hereinbefore risks racing of the motors coupled to one of its groups of displacement members, front or rear.
It is an essential object of the invention to eliminate this risk of racing and thus to allow the vehicle equipped with such motors to move in complete safety whatever the terrain, including going down a slope in forward gear and in reverse.